如何显示从FTP服务器C＃获取的图像
问题描述：
string memberpic = @"ftp://111.111.111.111/abc.jpg";
string ftpUser = "1111";
string ftpPassWord = "11111";
FtpWebRequest displayRequest = (FtpWebRequest)WebRequest.Create(memberpic);
displayRequest.Method = WebRequestMethods.Ftp.DownloadFile;
displayRequest.Credentials = new NetworkCredential(ftpUser, ftpPassWord);
FtpWebResponse displayResponse = (FtpWebResponse)displayRequest.GetResponse();
Stream responcestream = displayResponse.GetResponseStream();
FileStream fs = new FileStream(memberpic, FileMode.Create);
//it show error msg:The given path's format is not supported.
byte[] buffer = new byte[102400];
int read = 0;
do
{
read = responcestream.Read(buffer, 0, buffer.Length);
fs.Write(buffer, 0, read);
fs.Flush();
imgmemberpic.ImageUrl = memberpic;
}
while (!(read == 0));
fs.Flush();
fs.Close();
displayResponse.Close();
responcestream.Close();
答
你好，
您正在读取文件并将其存储到字节缓冲区中。返回数据不是URL，因此不会显示图像。您可以尝试将此字节缓冲区保存到磁盘文件中，并将该文件的URL分配给图像控件。
对于web，有一个规范来发送内联图像数据（base64编码），但并非所有浏览器都实现它。我知道Firefox支持它。
问候，
Hello,
You are reading the file and storing it into a byte buffer. The return data will not be a URL and hence the image wont be displayed. What you can try is to save this byte buffer into a disk file, and assign the URL of that file to image control.
For web there is a specification to send inline image data (base64 encoded), but not all browsers implement it. I know Firefox supports it.
Regards,
GetImage.ashx
//使用Handler
]]>
使用System;
使用System.Web ;
使用System.Data;
使用System.Configuration;
使用System.Web;
使用System .Web.Security;
使用System.Web.UI;
使用System.Web.UI.WebControls;
使用System.Web。 UI.WebControls.WebParts;
使用System.Web.UI.HtmlControls;
使用System.IO;
使用System.Net;
使用System.Data.Sql;
使用System.Data.SqlClient;
public class GetImage：IHttpHandler {
public string constr =Data Source = 111.111.111.111; Initial Catalog = musicnot_musicnote; Persist Security Info = True; User ID = 111;密码= 111;
//用于mssql连接
public void ProcessRequest （HttpContext context）{
// for ftp connenction
string FileSaveUri = @ftp://111.111.111.111/httpdocs/uploadpic/;
string ftpUser =111;
string ftpPassWord =111;
FtpWebRequest displayRequest =（ FtpWebRequest）WebRequest.Create（new Uri（FileSaveUri + context.Request.QueryString [memberpic]））;
displayRequest.Method = WebRequestMethods.Ftp.DownloadFile;
displayRequest.Credentials = new NetworkCredential（ftpUser，ftpPassWord）;
try
{
FtpWebResponse response =（ FtpWebResponse）displayRequest.GetResponse（）;
Stream Stream = response.GetResponseStream（）;
byte [] bytes = new byte [10240];
int i = 0;
MemoryStream mStream = new MemoryStream（）;
do
{
i = Stream.Read（bytes，0，bytes.Length）;
mStream.Write（bytes，0，i）;
} while（i！= 0）;
context.Response.Clear（）;
context.Response.ClearHeaders（）;
context.Response.ClearContent（）;
context.Response.ContentType =image / jpeg;
context.Response.BinaryWrite（mStream.GetBuffer（））;
}
catch（WebException wex）
{
}
catch（exception ex）
{
抛出新的异常（发生错误+ ex）;
}
}
public bool IsReusable {
get {
返回false;
}
}
}
displaypic.aspx.cs
使用（SqlConnection condatabase = new SqlConnection（constr））
{
SqlDataAdapter dtacheck;
dtacheck = new SqlDataAdapter（select * from memberlist where member_id =''+ Convert.ToString（Session [username] +''），condatabase）;
DataSet dscheck = new DataSet（）;
dtacheck.Fill（dscheck，memberlist）;
gvpic.DataSource = dscheck.Tables [memberlist];
gvpic.DataBind（）;
}
displaypic.aspx.cs
< asp：gridview id =gvpicrunat =serverautogeneratecolumns =False showheader =Falsexmlns：asp =＃unknown>
< columns>
< asp：templatefield>
< itemtemplate>
< asp：image runat =serverwidth =200height =200imageurl =<％＃〜=getimage.ashx？memberpic =+ Eval（member_pic）=％& gt;=id =memberpic>
终于可以工作了:)希望可以帮助其他人在未来解决这个问题
GetImage.ashx
// using Handler
]]>
using System;
using System.Web;
using System.Data;
using System.Configuration;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
using System.IO;
using System.Net;
using System.Data.Sql;
using System.Data.SqlClient;
public class GetImage : IHttpHandler {
public string constr = "Data Source=111.111.111.111;Initial Catalog=musicnot_musicnote;Persist Security Info=True;User ID=111;Password=111";
// for mssql connenction
public void ProcessRequest (HttpContext context) {
// for ftp connenction
string FileSaveUri = @"ftp://111.111.111.111/httpdocs/uploadpic/";
string ftpUser = "111";
string ftpPassWord = "111";
FtpWebRequest displayRequest = (FtpWebRequest)WebRequest.Create(new Uri(FileSaveUri + context.Request.QueryString["memberpic"]));
displayRequest.Method = WebRequestMethods.Ftp.DownloadFile;
displayRequest.Credentials = new NetworkCredential(ftpUser, ftpPassWord);
try
{
FtpWebResponse response = (FtpWebResponse)displayRequest.GetResponse();
Stream Stream = response.GetResponseStream();
byte[] bytes = new byte[10240];
int i = 0;
MemoryStream mStream = new MemoryStream();
do
{
i = Stream.Read(bytes, 0, bytes.Length);
mStream.Write(bytes, 0, i);
} while (i != 0);
context.Response.Clear();
context.Response.ClearHeaders();
context.Response.ClearContent();
context.Response.ContentType = "image/jpeg";
context.Response.BinaryWrite(mStream.GetBuffer());
}
catch (WebException wex)
{
}
catch (Exception ex)
{
throw new Exception("An Error Occurred" + ex);
}
}
public bool IsReusable {
get {
return false;
}
}
}
displaypic.aspx.cs
using (SqlConnection condatabase = new SqlConnection(constr))
{
SqlDataAdapter dtacheck;
dtacheck = new SqlDataAdapter("Select * from memberlist where member_id=''" + Convert.ToString(Session["username"] + "''"), condatabase);
DataSet dscheck = new DataSet();
dtacheck.Fill(dscheck, "memberlist");
gvpic.DataSource = dscheck.Tables["memberlist"];
gvpic.DataBind();
}
displaypic.aspx.cs
<asp:gridview id="gvpic" runat="server" autogeneratecolumns="False" showheader="False" xmlns:asp="#unknown">
<columns>
<asp:templatefield>
<itemtemplate>
<asp:image runat="server" width="200" height="200" imageurl="<%# " ~="" getimage.ashx?memberpic=" + Eval(" member_pic")="" %>"="" id="memberpic">
Finally can work :) hope can help other ppl solve this problem in furture